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Unix
Unix is a family of operating systems primarily designed for servers, mainframes, and high-end workstations. First created in 1969, Unix systems are renowned for their security and stability.
1,127 Questions
Unix is one of the more secure operating systems, but it would be difficult to give an exact answer. It is very easy (and possible) to make any operating system insecure.
It takes individuals some amount of time to secure any operating system, and Unix is no exception to that.
When the shell finds met a character in the command line what does it do?
The shell interpreter must substitute or convert all metacharacters in the command line before the command parameters are given to a program. Once all metacharacters have been removed and replaced by their equivalents the program is then executed.
What is the function of the Unix kernel?
The kernel is the essential center of a computer operating system, the core that provides basic services for all other parts of the operating system. A synonym is nucleus. A kernel can be contrasted with a shell, the outermost part of an operating system that interacts with user commands. Kernel and shell are terms used more frequently in Unix operating systems than in IBM mainframe or Microsoft Windows systems.
Defnition from Wikipedia:
In computer science, the kernel is the central component of most computer operating system(OS). Its responsibilities include managing the system's resources (the communication between hardware and software components). As a basic component of an operating system, a kernel provides the lowest-level abstraction layer for the resources (especially memory, processors and I/O devices) that application software must control to perform its function. It typically makes these facilities available to application programs through interprocess communication mechanisms and system calls.
These tasks are done differently by different kernels, depending on their design and implementation. While monolithic kernels will try to achieve these goals by executing all the code in the same address space to increase the performance of the system, microkernels run most of their services in user space, aiming to improve maintainability and modularity of the codebase. A range of possibilities exists between these two extremes.
"Linux" as a operating system distribution (which includes the kernel as created by Linus Torvalds), was in some way influenced by Unix (this includes Apple's Mac OS and OS X, which was based on BSD, which was derived from Unix) at some point in their development.
Without changing users home directory how to create a user in AIX?
Just like every administrative task: via smitty (or with command useradd).
or
Login to (or telnet to) node. (From a PC, click "Start" and "Run". Type "cmd" and click "OK". Type "telnet node", where "node" is the name of the node to login to.)
Type "root", depress "Enter", type "password", and depress "Enter", where "password" is root's password (see node administrator for password).
2. Execute SMIT.
Type "smitty" at the command prompt and depress "Enter".
3. Use the down arrow till you highlight "Security and Users" and depress "Enter". Use the down arrow till you highlight "Users". Depress "Enter". Use the down arrow till you highlight "Add a User". Depress "Enter". Enter the "userid" in the "User NAME" prompt, and depress "Enter", where userid is the account that you want to create. Currently, we are using the same account name as is used to logon to the mainframe. Depress "Esc" and "3", simultaneously, two (2) times, to repeat for other users or to exit from adding a new user.
4. Once you have entered all the new userids, use the down arrow till you highlight "Change a User's Password" and depress "Enter". Depress "Esc" and "3", simultaneously, to enter more new userids passwords or to exit from changing a user's password.
5. Depress "Esc" and "3", simultaneously, to enter the users (userids) into their proper groups. Use the down arrow till you highlight "Groups" and depress "Enter".
Use the down arrow till you highlight "Change/Show Characteristics of a Group" and depress "Enter". Type "group" in "Group NAME" prompt, where "group" is one of three (currently) categories, depending on the user's access needs.
After you have added or changed users (userids) to the correct group, then depress "Esc" and "3", simultaneously, to exit "SMIT".
6. Login to each new user account on AIX (UNIX) (using step #1). Change the account password to the same as the userid (current standard).
What is the program to calculate factorial value of given number using BC command in UNIX?
From the manpage of the bc(1) command:
The following is the definition of the recursive factorial function.
define f (x) {
if (x <= 1) return (1);
return (f(x-1) * x);
}
So you could enter that definition of f(), and then call it, for example f(10)
Is Linux more secure than Unix?
Even in the early days when Linux first came out, it was often commented upon how much faster it was than traditional Unix systems. For many tasks, Linux simply performs better. There are some situations that Linux still has not been optimized for, though, so Unix systems are used to do the "heavy" lifting.
How do you rearrange files in Unix?
What are you referring to by "rearrange?" Files are displayed in alphabetical order; to "rearrange" them, you would simply change their name.
How do you install Pentaho BI in Unix?
The Pentaho BI Project provides enterprise-class reporting, analysis, dashboard, data mining and workflow capabilities that help organizations operate more efficiently and effectively. The software offers flexible deployment options that enable use as embeddable components, customized BI application solutions, and as a complete out-of-the-box, integrated BI platform. Ranked #1 in Open Source Business Intelligence.
The installation URL is as follows,
http://wiki.pentaho.org/display/PentahoDoc/Manual+Deployment+of+Pentaho
What operating system often used for server applications is a scaled-down version of unix?
This unenlightened question is found on many A+ certification exams, First, I will tell you the that they want. Then I will tell you why there is no correct .
The that they want you to write in is "Linux." This is in spite of the fact that Linux scales even higher than Unix and has more features, thereby making most Unix implementations the "scaled-down" operating system.
In order for something to be legally called a "version of Unix", it must undergo a rigorous certification process. No Linux distro has ever undergone this process, and so cannot be called a "version" of Unix. So then you would have to look at what certified Unix systems are commonly used in the server market. The only certified Unix systems still commonly used on the server market are Solaris 10, AIX and Mac OS X. All three of these systems scale very highly, which makes them unsuitable as an .
Is compiler a part of operating system?
compiler basically translator of one language to desired languages...ex-c language to m/c redable format and os is a system software which provides interfaces between applicaton programs and hardware....so os is a interface unit system software and compiler just a translator....
Why is the Unix operating system virus free?
First of all, Unix (and even Linux) is NOT virus free. Although rare, there are viruses for such systems.
One of the primary reasons that Unix / Linux do not get as many viruses is that the ability of different users is limited. Non-technical users will be restricted in their ability to install, run, or modify software. More experienced users will usually be given more privileges. Without inexperienced users installing software at a whim, over 90 % of the threat of viruses and malware is removed.
Linux is even further protected against viruses because Linux is by nature a heterogeneous platform. To be effective, the program would have to be capable of affecting multiple versions of the kernel, and use exploits in a variety of programs.
What does the command kill -9 do in Unix?
Kill is a program that can terminate or send a signal to process.
kill -9 pid
Would send signal 9 to process having specific pid. 9 Means KILL signal that is not catchable or ignorable. In other words it would signal process (some running application) to quit immediately.
pid - process identifier.
How do you find your IP address from a UNIX command line?
Steps to be followed for finding your computer's ip address in Windows XP:
1.Start->Run->cmd prompt
2.In that,just type ipconfig and then click enter
For example: It will show ip address like 74.110.208.65 .
You can also find your IP address by using Ip-details.com .
What is unix schedular and how it work?
There are two standard job schedulers in Unix - 'at' and 'cron'. Neither can be answered in a short answer so it is suggested that you do an internet search on either of these two commands, or use the 'man' or 'info' command on 'at' or 'cron' on your Unix/Linux system.
What are the advantages of unix os over ms-dos os?
Yes and no. If you have the hardware resources to run UNIX/Linux then you should. DOSBox can run any DOS program in UNIX, so there is no need for DOS if you can run UNIX. However, if you have an older computer or an embedded system where UNIX or Linux would have too much overhead, DOS is a better choice.
What are the charateristics of UNIX operating system?
The UNIX Operating System is available on machines with a wide range of computing power, from microcomputers to mainframes, and on different manufacture's machines. No other operating system can make this claim. We see the reasons of popularity and success of UNIX.
The reasons are
Portability:
The system is written in high-level language making it easier to read, understand, change and, therefore move to other machines. The code can be changed and complied on a new machine. Customers can then choose from a wide variety of hardware vendors without being locked in with a particular vendor.
Machine-independence:
The System hides the machine architecture from the user, making it easier to write applications that can run on micros, mins and mainframes.
Multi-User Operations:
UNIX is a multi-user system designed to support a group of users simultaneously. The system allows for the sharing of processing power and peripheral resources, white at the same time providing excellent security features.
Hierarchical File System:
UNIX uses a hierarchile file structure to store information. This structure has the maximum flexibility in grouping information in a way that reflects its natural state. It allows for easy maintenance and efficient implementation.
UNIX shell:
UNIX has a simple user interface called the shell that has the power to provide the services that the user wants. It protects the user from having to know the intricate hardware details.
Pipes and Filters:
UNIX has facilities called Pipes and Filters which permit the user to create complex programs from simple programs.
Utilities:
UNIX has over 200 utility programs for various functions. New utilities can be built effortlessly by combining existing utilities.
Software Development Tools:
UNIX offers an excellent variety of tools for software development for all phases, from program editing to maintenance of software,
Data structures that contain information about files in Unix file systems that are created when a file system is created. Each file has an inode and is identified by an inode number (i-number) in the file system where it resides. inodes provide important information on files such as user and group ownership, access mode (read, write, execute permissions) and type
How many different kill signals can a kill command signal send to a certain process?
This varies depending on which system you are speaking about. The easiest way to find the signals are to issue a "kill -l" command (that is a small el, not a digit 1).
Why unix is a multiprogramming os?
Those are two separate and totally unrelated concepts.
Linux and Unix are considered multi-user systems because they support separate user accounts with different levels of access privilege. A single-user system may have more than one "account", but there is no administrative difference between them.
Linux and most modern versions of Unix are multiprocessing operating systems because they support more than one processor in a system and can allocate processes to different processors.
How does vi editor work in unix?
The Linux 'vi editor' is an editor that is text based. It can be used like notepad in Windows based systems. It can also be used for editing configuration files.
Different types of file in unix?
Regular file
Text or binary data
Directory
Contains other files and directories.
Executable file
File with the "execute permission" set
Symbolic link
File is a "shortcut" that points to another file.
Device special file
An interface to a piece of hardware, such as a printer.(In UNIX devices are treated as "files")
Named pipe
An interface to a network program.
"Best" is often a matter of opinion, and can be highly subjective. Mac OS X, Solaris 10, AIX,and z/OS are the only major certified Unix operating systems still under development. Mac OS X is the most popular Unix desktop, and Solaris 10 is the most popular one on large servers.
What is the command to run a unix program?
Just type the name of the program. If you want to run the dump program, type dump. if you want to open the links web browser, type links. .....
Some programs take arguments, for example the cat program accepts one or more files as an argument, so you could call it by typing
$ cat file1 [file2, file3...]
